Coal washing apparatus



' w. BURN TT,- JR

COALWASHING APPARATUS Filed July 8,1938 1 Patented Aug. 26, 1941 COAL WASHING APPARATUS William Burnett, Jr., Marion, Ill., assignor'to Peabody Coal Company, Chicago, 111., a corporation of Illinois Application July 8, 1938, Serial No. 218,042

Claims. (01. 209496) The present invention relates in general to coal washing apparatus and in particular is concerned with improvements in means for controlling the depth of the refuse bed in such apparatus of the type in which the washing operation results in a stratification of the coal and refuse such as bone, slate etc., as a result of the diflerent specific gravities of the materials.

Heretofore various schemes have been proposed for controlling the withdrawal of refuse material in coal washers of the hereindescribed type, wherein the coal and refuse therein are stratified into superposed layers according to their specific gravities.

One control scheme now being utilized for such apparatus embodies an expensive and complicated arrangement of relays which are controlled by an initiating medium in the form of a light beam which is directed upon a photo-electric cell. Control of the withdral of refuse is effected by permitting this beam to fall on the photoelectric cell under certain conditions of operation, while the beam is intercepted during certain other predetermined conditions of operation.

The above-described control arrangement has been found to be primarily objectionable in that due to its complicacy and the delicacy and technical nature of its parts; it is not easy to locate and remedy troubles when something goes wrong with its operation. Moreover, persons with the required skill necessary to understand and correct such troubles are seldom available on short notice. Thus, valuable time may be lost and 'the apparatus rendered idle and non-productive for a considerable period of time, whereas, with a simple control arrangement such as embodied in the present invention, an ordinary electrician may, within a comparatively short time, remedy most if not all of the troubles which might develop, and the operation of the washing apparatus quickly resumed.

Having in mind the foregoing objection as well as other objections topresent control arrangements, including the control arrangement described above, it is an object of the present invention to provide a simple, inexpensive and reliable means for controlling the operation of the refuse gate motor.

It is a further object to provide in a coal washer of the hereindescribed type, improved means for controlling the operation of the refuse gate as a function of the quantity of refuse being removed from the coal.

A still further object is to provide in such apparatus improved control means including a fioatmechanism which may be readily adjusted as to its specific gravity to conform to the specific gravity of the refuse material being drawn off.

It is also an object to provide improved means for damping the movement of the float mechanism during the washing operation, whereby its inertia may be varied independently of its specific gravity.

A still further object is to provide a switch control mechanism in which the operation of the switch is in timed relation to the means for measuring the depth of refuse layer, and so arrange the control mechanism that the timed relation of the switch operation may be varied with respect to such means.

Other objects and features of the invention will more fully appear from the following detailed description, taken in connection with the accompanying drawing, which illustrates a single embodiment thereof, and in which:

Figure 1 is an elevational View of one type of coal washer with which the present invention may be utilized, certain of the parts being shown in section to disclose the relationship of its associated parts; Figure 2 is a fragmentary view including a section through the bed of material being washed in the Washer, and showing the various parts of the present invention and the manner in which they are associated with the washing apparatus; and Figure 3 is an enlarged fragmentary detail view showing the manner in which the control switch of the present invention is mounted, and means whereby this switch may be adjusted to vary its operating characteristics.

As shown on the drawing:

The washing and separating apparatus with which the present invention is illustrated as being incorporated comprises a frame structure [0 which supports a vat or container II having a transversely rounded or curved bottom.

At its top and extending longitudinally of the container is a lateral compartment I2 defined by a longitudinally extending partition l3 and a cover plate or structure M which extends from the partition to the upper edge of one side of the container. It will be noted that the partition l3 does not extend entirely to the bottom of the container but is upwardly spaced therefrom to form a water passage. This construction in effect forms a U-shaped channel in which the legs are in close proximity, being separated by the common partition I3.

Extending from this partition to the other side of the container is a supporting structure I5 which may constitute a screen arrangement or grid of suitable construction for supporting a coal bed thereabove.

The side wall of the container H associated with the coal bed is extended above the washing bed and cooperates with an inwardly spaced side wall I6 and suitable end walls to define a receiving box for the coal or material to be washed. porting the material is inclined towards one end As shown in Figure 2, the screen bed for supof the box structure and is provided at the bottom of this end with a discharge outlet IT for receiving refuse. This discharge outlet is controlled by a star gate it of the usual construction. A motor I 9 is provided for rotating the star gate.

Disposed a suitable distance above the discharge outlet I7 is a second discharge outlet 20 through which the coal or other material relieved of its refuse is removed.

In order to cause a movement of the water in the container H through the coal or material bed, the chamber 12 is connected through the plate M with a conduit 2| by which compressed air may be admitted to the chamber l2. A suitable water inlet 22 is connected to the chamber 12, this inlet being provided with suitable control and connected to a suitable supply.

By admitting compressed air to the chamber l2 from suitable blower equipment and a pulsation air Valve, the water in the container H may be pulsated back and forth through the U-shaped channel so 'as to rise and fall through the material bed.

During these pulsations the material bed will be raised and lowered with each pulsation, and due to the difference in specific gravity of the coal and refuse materials contained therein, the coal and refuse will be stratified, as shown in Figure 2, the refuse forming a layer adjacent the screen or grid i5 and the coal forming in a layer superposed on the refuse layer.

The height of the refuse layer is determined by means of a float 23 which is supported on the end of a rod 24 supported for vertical movement in rollers 25-45.

By constructing this float so that its specific gravity conforms to the specific gravity of the refuse material to be drawn off, the float will rest on the top surface of the refuse layer and will rise and fall with it during the washing operation. Accordingly, as the refuse layer increases or decreases in depth, the rod 24 will be raised and lowered. Moreover, it will be evident that through the operation of the star gate 3, the depth of the refuse layer may be controlled so that it will at no time rise to suflicient depth to enable refuse to pass out of the discharge opening 20.

In the present invention, which is particularly concerned with means for controlling the operation of the gate [8, the rod 24 is provided at its upper end with an extension 26 which will rise and fall with the rod 24. The rod 24 is limited for rising and falling movement by means of vertically spaced stops 2'! and 28 between which an extension 29 carried by the rod 24 is adapted to move.

A rocker arm 35 is pivotally supported intermediate its ends on an upright member 3| disposed adjacent the extension 25. One end of this rocker arm is connected to the extension 26, and by providing a series of holes in the upper end of the extension the associated end of the rocker arm 38 may be variably connected to the extension so that for any position of the float, the angular position of the rocker arm may be varied.

A beam 32 is carried by the rocker arm 30, this beam providing a guide for a weight member 33 which may be longitudinally shifted along the beam 32 and secured in adjusted position by a set screw 34. Adjustment of this weight will vary the effective specific gravity of the float S2 to accommodate the same to refuse materials of different specific gravities.

For controlling the gate motor I9, a tilt switch 35, which may be of the mercury type, is supported on the rocker arm 30 so that it will be tilted to on and off positions in response to the rocking movements of the rocker arm.

In general this switch is so disposed that its contacts will be open for normal depth of the refuse layer, but as this layer builds up and approaches the discharge outlet 20, the resulting raised position of the float 23 will rock the arm 30 to such position as to move the switch 35 to closed position of its contacts.

A line contactor 36 has an operating coil 31 connected in series with the switch 35 across a suitable electric supply circuit 38.

The main contacts of contactor 36 are disposed in the supply circuit to the motor l9, in this case the supply circuit being a three-phase circuit as indicated at 39. Closure of the contacts of switch 35 Will energize the operating coil 31, whereupon the line contactor will close and con meet the motor to its energizing circuit. Operation of the motor will actuate the star gate in the proper direction to cause a discharge of refuse material through the discharge outlet H, with the result that the depth of the refuse layer is decreased. When the depth of this layer is decreased the required amount, the switch 35 Will have assumed a position in which its contacts will open, thus stopping the motor 19 and preventing further discharge through the gate [8.

In most cases, the variable connection of the rocker arm 30 to the extension 24 is sufficient to vary the timed relation of the opening and closing of the contacts of switch 35 with reference to the movement of the float 23. However, it has been found that there may be times when a finer adjustment of this timed relation may be desirable. For such purpose, the switch 35 may be arranged for angular adjustment relative to the rocker arm 3!].

This is accomplished by mounting the switch in suitable contact clips 40 which may be affixed in any suitable manner to a plate 4|. This plate is pivoted at one end on a pivot member 42 for swinging movement. The opposite end of the plate is provided with a curved slot 43 in which a bolt 44 is disposed, and by means of an associated nut 45 the plate may be secured in adjusted angular relation to the rocker arm 30.

In order to apprise the operator of the adjusted position of the plate 4| and serve as a guide for making adjustments of this plate, the plate may be provided with an indicating pointer 46 which is cooperatively associated with suitable scale 4? on the arm 30.

It has been found that when washing large sized co al, more violent impulses of water move ment are required. Since the apparatus depends upon the different specific gravities of the coal and refuse for its proper operation, some means must be provided in which the inertia effect of the float may be varied while maintaining its weight or specific gravity to appropriate value.

For such purpose, the float movement is dampened by a dashpot, generally indicated at 48, which may have its piston 49 connected with the rocker arm 30. This dashpot may be of any suitable type or construction and for this purpose I h ave found it satisfactory to use a dashpot of the oil or liquid type. In order to adjust the dampening effect of the dashpot, the opposite ends of the cylinder which cooperates with the piston may be connected through a conduit having a valve 5| disposed therein. By adjusting the valve, movement of the liquid through the conduit 53 from one side of the piston to the other during the operation of the dashpot may be more or less impeded to secure the proper dampening effect for any desired condition of operation.

The use of the adjustable weight 33 has also been found to be advantageous in that should the float, through accident or for some other reason, have its specific gravity changed by the leakage of water thereinto, the change in specific gravity can immediately be compensated for by adjustment of the weight. Thus the operation of the apparatus could be temporarily continued until the trouble could be remedied, thus avoiding an extended shut-down.

From the foregoing description, it will be apparent that the present invention provides a simple, inexpensive and reliable means for controlling the operation of the refuse gate motor, whereby the withdrawal of refuse from the refuse layer may be controlled as a function of the quantity of refuse being removed from the coal; apparatus which includes an improved float mechanism which may be readily adjusted as to its specific gravity to conform to the specific gravity of the refuse material; which embodies improved means for damping the movement of the float mechanism during the washing operation, whereby the inertia of the float mechanism may be varied independently of its specific gravity; and in which the timed relation of the operation of the control equipment with reference to the movements of the float may be varied to adapt the control mechanism for different conditions of operation of the apparatus.

It is, of course, to be understood that althou h I have described in detail the preferred embodiments of my invention, the invention is not to be thus limited but only insofar as defined by the scope and spirit of the appended claims.

I claim as my invention:

1. Coal washer apparatus arranged to s ratify the coal and refuse therein into layers in accordance with the respective specific gravities of said coal and refuse, said apparatus comprising a member supported for movement in accordance with changes in depth of the refuse layer, a rocker arm having one end connected to said member, a tilt switch mounted on said arm for rocking movement therewith, means for varying the angular relation of said switch with respect to said arm, and means including an electric driving motor controlled by said switch [or withdrawing refuse from said refuse layer.

2. Coal washer apparatus arranged to stratify the coal and refuse therein into layers in accordance with the respective specific gravities of said coal and refuse, said apparatus comprising a member supported for movement in accordance with changes in depth of the refuse layer, a pivotally mounted arm rocked by said member, a tilt switch mounted on said arm for rocking movement therewith, means for varying the angular positions of said switch on said arm, means including an electric driving motor controlled by said switch for withdrawing refuse from said refuse layer, and means for indicating the angul-ar positions of said switch.

3. Coal washer apparatus arranged to stratify the coal and refuse therein into layers in accordance with the respective specific gravities of said coal and refuse, said apparatus comprising a member supported for movement in accordance with changes in depth of the refuse layer, a rocker arm pivoted between its ends and actuated directly by said member, a weight member supported for adjustment longitudinally of said arm to either side of its pivot, switch means responsive to the movement of said arm, and means including an electric driving motor controlled by said switch for withdrawing refuse from said refuse layer.

4. Means for controlling the operation of a motor driven refuse discharge gate in a coal washer arranged to stratify the coal and refuse particles according to their specific gravities, said means comprising a float raised and lowered in response to variations in the depth of the refuse layer, a pivoted arm rocked by the float movements, means for opening and closing an energizing circuit for said motor including a switch carried by said arm, said switch being actuable to open and closed positions in response to the rocking movement of the arm to different positions, and a weight movably adjustable along the pivoted arm between positions on either side of the arm pivot for varying the specific gravity of the float to compensate for variations in the specific gravity of the refuse.

5. Means for controlling the operation of a motor driven refuse discharge gate in a coal Washer arranged to stratify the coal and refuse particles according to their specific gravities; said means comprising a beam pivoted intermediate its ends for rocking movements, a float member arranged for raising and lowering move ments in response to variations in the depth of the refuse layer, said member having an adjustable pivotal connection with one end of the beam, damping means pivotally connected with the other end of the beam, a Weight member movably adjustable along the length of the beam between positions on either side of its pivot, and a switch carried by the beam for controlling an energizing circuit for said motor, said switch being actuable to opened and closed positions ly adjustable relative to the beam.

WILLIAM BURNETT, JR. 

